Image forming devices including copiers, laser printers, facsimile machines, and the like, include a photo conductive drum (hereinafter “photoconductor”) having a rigid cylindrical surface that is coated along a defined length of its outer surface. The surface of the photoconductor is typically charged to a uniform electrical potential and then selectively exposed to light in a pattern corresponding to an original image. The areas of the photoconductive surface exposed to light are discharged, thus forming a latent electrostatic image on the photoconductive surface. A developer material, such as toner, having an electrical charge such that the toner is attracted to the photoconductive surface is used for forming the image. The toner is normally stored in a reservoir adjacent to the photoconductor and is transferred to the photoconductor by the developer roll. The thickness of the toner layer on the developer roll may be controlled by a nip, which is typically formed between a doctor blade and the developer roll. A recording sheet, such as a blank sheet of paper, may then be brought into contact with the discharged photoconductive surface and the toner therein is transferred to the recording sheet in the form of the latent electrostatic image. The recording sheet may then be heated thereby permanently fusing the toner to the sheet. In preparation for the next image forming cycle, the photoconductive surface may be discharged and residual toner removed.
Maintaining consistent contact and pressure with the developer roll may be problematic due to the fact that the developer roll profile may be non-uniform and thus, require the doctor blade to possibly move inward and outward to track the surface of the developer roll. Additionally, contact may be maintained across the entire length of the doctor blade to ensure even print quality across the entire width of the image. One problem in some prior systems, may be the undesirable vibration caused by the contact of the doctor blade with the developer roll, especially towards the end of a cartridge's life which may cause jitter. This problem has been addressed in some products by applying a foam seal behind the doctor blade. However, the geometries/configurations of some products, which also suffer from that problem and noise caused by the vibration, do not allow for the placement of seals or any dampening materials/extensions behind the blade.